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* [FFmpeg-devel] [PATCH v6 3/3] avcodec/hevc: Add alpha layer support
@ 2025-02-11 10:40 Zhao Zhili
  2025-02-11 11:23 ` Andreas Rheinhardt
  0 siblings, 1 reply; 6+ messages in thread
From: Zhao Zhili @ 2025-02-11 10:40 UTC (permalink / raw)
  To: ffmpeg-devel; +Cc: Zhao Zhili

From: Zhao Zhili <zhilizhao@tencent.com>

Signed-off-by: Zhao Zhili <zhilizhao@tencent.com>
---
 libavcodec/hevc/hevcdec.c | 73 ++++++++++++++++++++++++++++++++++++++-
 libavcodec/hevc/hevcdec.h |  2 ++
 libavcodec/hevc/refs.c    | 34 +++++++++++++++++-
 3 files changed, 107 insertions(+), 2 deletions(-)

diff --git a/libavcodec/hevc/hevcdec.c b/libavcodec/hevc/hevcdec.c
index e9c045f7a1..f71edf213b 100644
--- a/libavcodec/hevc/hevcdec.c
+++ b/libavcodec/hevc/hevcdec.c
@@ -466,6 +466,25 @@ static int export_multilayer(HEVCContext *s, const HEVCVPS *vps)
     return 0;
 }
 
+int ff_hevc_is_alpha_video(const HEVCContext *s)
+{
+    const HEVCVPS *vps = s->vps;
+    int ret = 0;
+
+    if (vps->nb_layers != 2 || !vps->layer_id_in_nuh[1])
+        return 0;
+
+    /* decode_vps_ext() guarantees that SCALABILITY_AUXILIARY with AuxId other
+     * than alpha cannot reach here.
+     */
+    ret = (s->vps->scalability_mask_flag & HEVC_SCALABILITY_AUXILIARY);
+
+    av_log(s->avctx, AV_LOG_DEBUG, "Multi layer video, %s alpha video\n",
+           ret ? "is" : "not");
+
+    return ret;
+}
+
 static int setup_multilayer(HEVCContext *s, const HEVCVPS *vps)
 {
     unsigned layers_active_output = 0, highest_layer;
@@ -473,6 +492,18 @@ static int setup_multilayer(HEVCContext *s, const HEVCVPS *vps)
     s->layers_active_output = 1;
     s->layers_active_decode = 1;
 
+    if (ff_hevc_is_alpha_video(s)) {
+        const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(s->avctx->pix_fmt);
+
+        if (!(desc->flags & AV_PIX_FMT_FLAG_ALPHA))
+            return 0;
+
+        s->layers_active_decode = (1 << vps->nb_layers) - 1;
+        s->layers_active_output = 1;
+
+        return 0;
+    }
+
     // nothing requested - decode base layer only
     if (!s->nb_view_ids)
         return 0;
@@ -530,6 +561,34 @@ static int setup_multilayer(HEVCContext *s, const HEVCVPS *vps)
     return 0;
 }
 
+static enum AVPixelFormat map_to_alpha_format(HEVCContext *s,
+                                              enum AVPixelFormat pix_fmt)
+{
+    switch (pix_fmt) {
+    case AV_PIX_FMT_YUV420P:
+    case AV_PIX_FMT_YUVJ420P:
+        return AV_PIX_FMT_YUVA420P;
+    case AV_PIX_FMT_YUV420P10:
+        return AV_PIX_FMT_YUVA420P10;
+    case AV_PIX_FMT_YUV444P:
+        return AV_PIX_FMT_YUVA444P;
+    case AV_PIX_FMT_YUV422P:
+        return AV_PIX_FMT_YUVA422P;
+    case AV_PIX_FMT_YUV422P10LE:
+        return AV_PIX_FMT_YUVA422P10LE;
+    case AV_PIX_FMT_YUV444P10:
+        return AV_PIX_FMT_YUVA444P10;
+    case AV_PIX_FMT_YUV444P12:
+        return AV_PIX_FMT_YUVA444P12;
+    case AV_PIX_FMT_YUV422P12:
+        return AV_PIX_FMT_YUVA422P12;
+    default:
+        av_log(s->avctx, AV_LOG_WARNING, "No alpha pixel format map for %s\n",
+               av_get_pix_fmt_name(pix_fmt));
+        return AV_PIX_FMT_NONE;
+    }
+}
+
 static enum AVPixelFormat get_format(HEVCContext *s, const HEVCSPS *sps)
 {
 #define HWACCEL_MAX (CONFIG_HEVC_DXVA2_HWACCEL + \
@@ -540,9 +599,13 @@ static enum AVPixelFormat get_format(HEVCContext *s, const HEVCSPS *sps)
                      CONFIG_HEVC_VIDEOTOOLBOX_HWACCEL + \
                      CONFIG_HEVC_VDPAU_HWACCEL + \
                      CONFIG_HEVC_VULKAN_HWACCEL)
-    enum AVPixelFormat pix_fmts[HWACCEL_MAX + 2], *fmt = pix_fmts;
+    enum AVPixelFormat pix_fmts[HWACCEL_MAX + 3], *fmt = pix_fmts;
+    enum AVPixelFormat alpha_fmt = AV_PIX_FMT_NONE;
     int ret;
 
+    if (ff_hevc_is_alpha_video(s))
+        alpha_fmt = map_to_alpha_format(s, sps->pix_fmt);
+
     switch (sps->pix_fmt) {
     case AV_PIX_FMT_YUV420P:
     case AV_PIX_FMT_YUVJ420P:
@@ -664,6 +727,8 @@ static enum AVPixelFormat get_format(HEVCContext *s, const HEVCSPS *sps)
         break;
     }
 
+    if (alpha_fmt != AV_PIX_FMT_NONE)
+        *fmt++ = alpha_fmt;
     *fmt++ = sps->pix_fmt;
     *fmt = AV_PIX_FMT_NONE;
 
@@ -3194,6 +3259,12 @@ static int hevc_frame_start(HEVCContext *s, HEVCLayerContext *l,
                 !sps->vui.common.video_signal_type_present_flag)
                 pix_fmt = sps_base->pix_fmt;
 
+            // Ignore range mismatch between base layer and alpha layer
+            if (ff_hevc_is_alpha_video(s) &&
+                sps_base->pix_fmt == AV_PIX_FMT_YUV420P &&
+                pix_fmt == AV_PIX_FMT_YUVJ420P)
+                pix_fmt = sps_base->pix_fmt;
+
             if (pix_fmt     != sps_base->pix_fmt ||
                 sps->width  != sps_base->width   ||
                 sps->height != sps_base->height) {
diff --git a/libavcodec/hevc/hevcdec.h b/libavcodec/hevc/hevcdec.h
index 4e95035688..b2b725b5cd 100644
--- a/libavcodec/hevc/hevcdec.h
+++ b/libavcodec/hevc/hevcdec.h
@@ -714,6 +714,8 @@ void ff_hevc_hls_residual_coding(HEVCLocalContext *lc, const HEVCPPS *pps,
 
 void ff_hevc_hls_mvd_coding(HEVCLocalContext *lc, int x0, int y0, int log2_cb_size);
 
+int ff_hevc_is_alpha_video(const HEVCContext *s);
+
 extern const uint8_t ff_hevc_qpel_extra_before[4];
 extern const uint8_t ff_hevc_qpel_extra_after[4];
 extern const uint8_t ff_hevc_qpel_extra[4];
diff --git a/libavcodec/hevc/refs.c b/libavcodec/hevc/refs.c
index dd7f7f95a8..da0bac8d9c 100644
--- a/libavcodec/hevc/refs.c
+++ b/libavcodec/hevc/refs.c
@@ -79,6 +79,30 @@ void ff_hevc_flush_dpb(HEVCContext *s)
     }
 }
 
+static int replace_alpha_plane(AVFrame *alpha, AVFrame *base)
+{
+    AVBufferRef *base_a = av_frame_get_plane_buffer(base, 3);
+    uint8_t *data = alpha->data[0];
+    int ret;
+
+    for (int i = 0; i < FF_ARRAY_ELEMS(alpha->buf) && alpha->buf[i]; i++) {
+        AVBufferRef *buf = alpha->buf[i];
+
+        if (data >= buf->data && data < buf->data + buf->size) {
+            ret = av_buffer_replace(&alpha->buf[i], base_a);
+            if (ret < 0)
+                return ret;
+
+            alpha->linesize[0] = base->linesize[3];
+            alpha->data[0] = base->data[3];
+
+            return 0;
+        }
+    }
+
+    return AVERROR_BUG;
+}
+
 static HEVCFrame *alloc_frame(HEVCContext *s, HEVCLayerContext *l)
 {
     const HEVCVPS *vps = l->sps->vps;
@@ -103,7 +127,7 @@ static HEVCFrame *alloc_frame(HEVCContext *s, HEVCLayerContext *l)
         }
 
         // add view ID side data if it's nontrivial
-        if (vps->nb_layers > 1 || view_id) {
+        if (!ff_hevc_is_alpha_video(s) && (vps->nb_layers > 1 || view_id)) {
             HEVCSEITDRDI *tdrdi = &s->sei.tdrdi;
             AVFrameSideData *sd = av_frame_side_data_new(&frame->f->side_data,
                                                          &frame->f->nb_side_data,
@@ -161,7 +185,15 @@ static HEVCFrame *alloc_frame(HEVCContext *s, HEVCLayerContext *l)
         if (ret < 0)
             goto fail;
 
+
         frame->pps = av_refstruct_ref_c(s->pps);
+        if (l != &s->layers[0] && ff_hevc_is_alpha_video(s)) {
+            AVFrame *alpha = frame->f;
+            AVFrame *base = s->layers[0].cur_frame->f;
+            ret = replace_alpha_plane(alpha, base);
+            if (ret < 0)
+                goto fail;
+        }
 
         return frame;
 fail:
-- 
2.46.0

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^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [FFmpeg-devel] [PATCH v6 3/3] avcodec/hevc: Add alpha layer support
  2025-02-11 10:40 [FFmpeg-devel] [PATCH v6 3/3] avcodec/hevc: Add alpha layer support Zhao Zhili
@ 2025-02-11 11:23 ` Andreas Rheinhardt
  2025-02-11 11:49   ` Zhao Zhili
  0 siblings, 1 reply; 6+ messages in thread
From: Andreas Rheinhardt @ 2025-02-11 11:23 UTC (permalink / raw)
  To: ffmpeg-devel

Zhao Zhili:
> From: Zhao Zhili <zhilizhao@tencent.com>
> 
> Signed-off-by: Zhao Zhili <zhilizhao@tencent.com>
> ---
>  libavcodec/hevc/hevcdec.c | 73 ++++++++++++++++++++++++++++++++++++++-
>  libavcodec/hevc/hevcdec.h |  2 ++
>  libavcodec/hevc/refs.c    | 34 +++++++++++++++++-
>  3 files changed, 107 insertions(+), 2 deletions(-)
> 
> diff --git a/libavcodec/hevc/hevcdec.c b/libavcodec/hevc/hevcdec.c
> index e9c045f7a1..f71edf213b 100644
> --- a/libavcodec/hevc/hevcdec.c
> +++ b/libavcodec/hevc/hevcdec.c
> @@ -466,6 +466,25 @@ static int export_multilayer(HEVCContext *s, const HEVCVPS *vps)
>      return 0;
>  }
>  
> +int ff_hevc_is_alpha_video(const HEVCContext *s)
> +{
> +    const HEVCVPS *vps = s->vps;
> +    int ret = 0;
> +
> +    if (vps->nb_layers != 2 || !vps->layer_id_in_nuh[1])
> +        return 0;
> +
> +    /* decode_vps_ext() guarantees that SCALABILITY_AUXILIARY with AuxId other
> +     * than alpha cannot reach here.
> +     */
> +    ret = (s->vps->scalability_mask_flag & HEVC_SCALABILITY_AUXILIARY);
> +
> +    av_log(s->avctx, AV_LOG_DEBUG, "Multi layer video, %s alpha video\n",
> +           ret ? "is" : "not");
> +
> +    return ret;
> +}
> +
>  static int setup_multilayer(HEVCContext *s, const HEVCVPS *vps)
>  {
>      unsigned layers_active_output = 0, highest_layer;
> @@ -473,6 +492,18 @@ static int setup_multilayer(HEVCContext *s, const HEVCVPS *vps)
>      s->layers_active_output = 1;
>      s->layers_active_decode = 1;
>  
> +    if (ff_hevc_is_alpha_video(s)) {
> +        const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(s->avctx->pix_fmt);
> +
> +        if (!(desc->flags & AV_PIX_FMT_FLAG_ALPHA))
> +            return 0;
> +
> +        s->layers_active_decode = (1 << vps->nb_layers) - 1;
> +        s->layers_active_output = 1;
> +
> +        return 0;
> +    }
> +
>      // nothing requested - decode base layer only
>      if (!s->nb_view_ids)
>          return 0;
> @@ -530,6 +561,34 @@ static int setup_multilayer(HEVCContext *s, const HEVCVPS *vps)
>      return 0;
>  }
>  
> +static enum AVPixelFormat map_to_alpha_format(HEVCContext *s,
> +                                              enum AVPixelFormat pix_fmt)
> +{
> +    switch (pix_fmt) {
> +    case AV_PIX_FMT_YUV420P:
> +    case AV_PIX_FMT_YUVJ420P:
> +        return AV_PIX_FMT_YUVA420P;
> +    case AV_PIX_FMT_YUV420P10:
> +        return AV_PIX_FMT_YUVA420P10;
> +    case AV_PIX_FMT_YUV444P:
> +        return AV_PIX_FMT_YUVA444P;
> +    case AV_PIX_FMT_YUV422P:
> +        return AV_PIX_FMT_YUVA422P;
> +    case AV_PIX_FMT_YUV422P10LE:
> +        return AV_PIX_FMT_YUVA422P10LE;
> +    case AV_PIX_FMT_YUV444P10:
> +        return AV_PIX_FMT_YUVA444P10;
> +    case AV_PIX_FMT_YUV444P12:
> +        return AV_PIX_FMT_YUVA444P12;
> +    case AV_PIX_FMT_YUV422P12:
> +        return AV_PIX_FMT_YUVA422P12;
> +    default:
> +        av_log(s->avctx, AV_LOG_WARNING, "No alpha pixel format map for %s\n",
> +               av_get_pix_fmt_name(pix_fmt));
> +        return AV_PIX_FMT_NONE;
> +    }
> +}
> +
>  static enum AVPixelFormat get_format(HEVCContext *s, const HEVCSPS *sps)
>  {
>  #define HWACCEL_MAX (CONFIG_HEVC_DXVA2_HWACCEL + \
> @@ -540,9 +599,13 @@ static enum AVPixelFormat get_format(HEVCContext *s, const HEVCSPS *sps)
>                       CONFIG_HEVC_VIDEOTOOLBOX_HWACCEL + \
>                       CONFIG_HEVC_VDPAU_HWACCEL + \
>                       CONFIG_HEVC_VULKAN_HWACCEL)
> -    enum AVPixelFormat pix_fmts[HWACCEL_MAX + 2], *fmt = pix_fmts;
> +    enum AVPixelFormat pix_fmts[HWACCEL_MAX + 3], *fmt = pix_fmts;
> +    enum AVPixelFormat alpha_fmt = AV_PIX_FMT_NONE;
>      int ret;
>  
> +    if (ff_hevc_is_alpha_video(s))
> +        alpha_fmt = map_to_alpha_format(s, sps->pix_fmt);
> +
>      switch (sps->pix_fmt) {
>      case AV_PIX_FMT_YUV420P:
>      case AV_PIX_FMT_YUVJ420P:
> @@ -664,6 +727,8 @@ static enum AVPixelFormat get_format(HEVCContext *s, const HEVCSPS *sps)
>          break;
>      }
>  
> +    if (alpha_fmt != AV_PIX_FMT_NONE)
> +        *fmt++ = alpha_fmt;
>      *fmt++ = sps->pix_fmt;
>      *fmt = AV_PIX_FMT_NONE;
>  
> @@ -3194,6 +3259,12 @@ static int hevc_frame_start(HEVCContext *s, HEVCLayerContext *l,
>                  !sps->vui.common.video_signal_type_present_flag)
>                  pix_fmt = sps_base->pix_fmt;
>  
> +            // Ignore range mismatch between base layer and alpha layer
> +            if (ff_hevc_is_alpha_video(s) &&
> +                sps_base->pix_fmt == AV_PIX_FMT_YUV420P &&
> +                pix_fmt == AV_PIX_FMT_YUVJ420P)
> +                pix_fmt = sps_base->pix_fmt;
> +
>              if (pix_fmt     != sps_base->pix_fmt ||
>                  sps->width  != sps_base->width   ||
>                  sps->height != sps_base->height) {
> diff --git a/libavcodec/hevc/hevcdec.h b/libavcodec/hevc/hevcdec.h
> index 4e95035688..b2b725b5cd 100644
> --- a/libavcodec/hevc/hevcdec.h
> +++ b/libavcodec/hevc/hevcdec.h
> @@ -714,6 +714,8 @@ void ff_hevc_hls_residual_coding(HEVCLocalContext *lc, const HEVCPPS *pps,
>  
>  void ff_hevc_hls_mvd_coding(HEVCLocalContext *lc, int x0, int y0, int log2_cb_size);
>  
> +int ff_hevc_is_alpha_video(const HEVCContext *s);
> +
>  extern const uint8_t ff_hevc_qpel_extra_before[4];
>  extern const uint8_t ff_hevc_qpel_extra_after[4];
>  extern const uint8_t ff_hevc_qpel_extra[4];
> diff --git a/libavcodec/hevc/refs.c b/libavcodec/hevc/refs.c
> index dd7f7f95a8..da0bac8d9c 100644
> --- a/libavcodec/hevc/refs.c
> +++ b/libavcodec/hevc/refs.c
> @@ -79,6 +79,30 @@ void ff_hevc_flush_dpb(HEVCContext *s)
>      }
>  }
>  
> +static int replace_alpha_plane(AVFrame *alpha, AVFrame *base)
> +{
> +    AVBufferRef *base_a = av_frame_get_plane_buffer(base, 3);
> +    uint8_t *data = alpha->data[0];
> +    int ret;
> +
> +    for (int i = 0; i < FF_ARRAY_ELEMS(alpha->buf) && alpha->buf[i]; i++) {
> +        AVBufferRef *buf = alpha->buf[i];
> +
> +        if (data >= buf->data && data < buf->data + buf->size) {

Pointer comparisons (other than equality/inquality comparisons) are
undefined behavior unless the two pointers point into the same array (or
one past the last element of an array).

> +            ret = av_buffer_replace(&alpha->buf[i], base_a);
> +            if (ret < 0)
> +                return ret;
> +
> +            alpha->linesize[0] = base->linesize[3];
> +            alpha->data[0] = base->data[3];
> +
> +            return 0;
> +        }
> +    }
> +
> +    return AVERROR_BUG;
> +}
> +
>  static HEVCFrame *alloc_frame(HEVCContext *s, HEVCLayerContext *l)
>  {
>      const HEVCVPS *vps = l->sps->vps;
> @@ -103,7 +127,7 @@ static HEVCFrame *alloc_frame(HEVCContext *s, HEVCLayerContext *l)
>          }
>  
>          // add view ID side data if it's nontrivial
> -        if (vps->nb_layers > 1 || view_id) {
> +        if (!ff_hevc_is_alpha_video(s) && (vps->nb_layers > 1 || view_id)) {
>              HEVCSEITDRDI *tdrdi = &s->sei.tdrdi;
>              AVFrameSideData *sd = av_frame_side_data_new(&frame->f->side_data,
>                                                           &frame->f->nb_side_data,
> @@ -161,7 +185,15 @@ static HEVCFrame *alloc_frame(HEVCContext *s, HEVCLayerContext *l)
>          if (ret < 0)
>              goto fail;
>  
> +
>          frame->pps = av_refstruct_ref_c(s->pps);
> +        if (l != &s->layers[0] && ff_hevc_is_alpha_video(s)) {
> +            AVFrame *alpha = frame->f;
> +            AVFrame *base = s->layers[0].cur_frame->f;
> +            ret = replace_alpha_plane(alpha, base);
> +            if (ret < 0)
> +                goto fail;
> +        }
>  
>          return frame;
>  fail:

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^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [FFmpeg-devel] [PATCH v6 3/3] avcodec/hevc: Add alpha layer support
  2025-02-11 11:23 ` Andreas Rheinhardt
@ 2025-02-11 11:49   ` Zhao Zhili
  2025-02-11 12:12     ` Andreas Rheinhardt
  0 siblings, 1 reply; 6+ messages in thread
From: Zhao Zhili @ 2025-02-11 11:49 UTC (permalink / raw)
  To: FFmpeg development discussions and patches



> On Feb 11, 2025, at 19:23, Andreas Rheinhardt <andreas.rheinhardt@outlook.com> wrote:
> 
> Zhao Zhili:
>> From: Zhao Zhili <zhilizhao@tencent.com>
>> 
>> Signed-off-by: Zhao Zhili <zhilizhao@tencent.com>
>> ---
>> libavcodec/hevc/hevcdec.c | 73 ++++++++++++++++++++++++++++++++++++++-
>> libavcodec/hevc/hevcdec.h |  2 ++
>> libavcodec/hevc/refs.c    | 34 +++++++++++++++++-
>> 3 files changed, 107 insertions(+), 2 deletions(-)
>> 
>> diff --git a/libavcodec/hevc/hevcdec.c b/libavcodec/hevc/hevcdec.c
>> index e9c045f7a1..f71edf213b 100644
>> --- a/libavcodec/hevc/hevcdec.c
>> +++ b/libavcodec/hevc/hevcdec.c
>> @@ -466,6 +466,25 @@ static int export_multilayer(HEVCContext *s, const HEVCVPS *vps)
>>     return 0;
>> }
>> 
>> +int ff_hevc_is_alpha_video(const HEVCContext *s)
>> +{
>> +    const HEVCVPS *vps = s->vps;
>> +    int ret = 0;
>> +
>> +    if (vps->nb_layers != 2 || !vps->layer_id_in_nuh[1])
>> +        return 0;
>> +
>> +    /* decode_vps_ext() guarantees that SCALABILITY_AUXILIARY with AuxId other
>> +     * than alpha cannot reach here.
>> +     */
>> +    ret = (s->vps->scalability_mask_flag & HEVC_SCALABILITY_AUXILIARY);
>> +
>> +    av_log(s->avctx, AV_LOG_DEBUG, "Multi layer video, %s alpha video\n",
>> +           ret ? "is" : "not");
>> +
>> +    return ret;
>> +}
>> +
>> static int setup_multilayer(HEVCContext *s, const HEVCVPS *vps)
>> {
>>     unsigned layers_active_output = 0, highest_layer;
>> @@ -473,6 +492,18 @@ static int setup_multilayer(HEVCContext *s, const HEVCVPS *vps)
>>     s->layers_active_output = 1;
>>     s->layers_active_decode = 1;
>> 
>> +    if (ff_hevc_is_alpha_video(s)) {
>> +        const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(s->avctx->pix_fmt);
>> +
>> +        if (!(desc->flags & AV_PIX_FMT_FLAG_ALPHA))
>> +            return 0;
>> +
>> +        s->layers_active_decode = (1 << vps->nb_layers) - 1;
>> +        s->layers_active_output = 1;
>> +
>> +        return 0;
>> +    }
>> +
>>     // nothing requested - decode base layer only
>>     if (!s->nb_view_ids)
>>         return 0;
>> @@ -530,6 +561,34 @@ static int setup_multilayer(HEVCContext *s, const HEVCVPS *vps)
>>     return 0;
>> }
>> 
>> +static enum AVPixelFormat map_to_alpha_format(HEVCContext *s,
>> +                                              enum AVPixelFormat pix_fmt)
>> +{
>> +    switch (pix_fmt) {
>> +    case AV_PIX_FMT_YUV420P:
>> +    case AV_PIX_FMT_YUVJ420P:
>> +        return AV_PIX_FMT_YUVA420P;
>> +    case AV_PIX_FMT_YUV420P10:
>> +        return AV_PIX_FMT_YUVA420P10;
>> +    case AV_PIX_FMT_YUV444P:
>> +        return AV_PIX_FMT_YUVA444P;
>> +    case AV_PIX_FMT_YUV422P:
>> +        return AV_PIX_FMT_YUVA422P;
>> +    case AV_PIX_FMT_YUV422P10LE:
>> +        return AV_PIX_FMT_YUVA422P10LE;
>> +    case AV_PIX_FMT_YUV444P10:
>> +        return AV_PIX_FMT_YUVA444P10;
>> +    case AV_PIX_FMT_YUV444P12:
>> +        return AV_PIX_FMT_YUVA444P12;
>> +    case AV_PIX_FMT_YUV422P12:
>> +        return AV_PIX_FMT_YUVA422P12;
>> +    default:
>> +        av_log(s->avctx, AV_LOG_WARNING, "No alpha pixel format map for %s\n",
>> +               av_get_pix_fmt_name(pix_fmt));
>> +        return AV_PIX_FMT_NONE;
>> +    }
>> +}
>> +
>> static enum AVPixelFormat get_format(HEVCContext *s, const HEVCSPS *sps)
>> {
>> #define HWACCEL_MAX (CONFIG_HEVC_DXVA2_HWACCEL + \
>> @@ -540,9 +599,13 @@ static enum AVPixelFormat get_format(HEVCContext *s, const HEVCSPS *sps)
>>                      CONFIG_HEVC_VIDEOTOOLBOX_HWACCEL + \
>>                      CONFIG_HEVC_VDPAU_HWACCEL + \
>>                      CONFIG_HEVC_VULKAN_HWACCEL)
>> -    enum AVPixelFormat pix_fmts[HWACCEL_MAX + 2], *fmt = pix_fmts;
>> +    enum AVPixelFormat pix_fmts[HWACCEL_MAX + 3], *fmt = pix_fmts;
>> +    enum AVPixelFormat alpha_fmt = AV_PIX_FMT_NONE;
>>     int ret;
>> 
>> +    if (ff_hevc_is_alpha_video(s))
>> +        alpha_fmt = map_to_alpha_format(s, sps->pix_fmt);
>> +
>>     switch (sps->pix_fmt) {
>>     case AV_PIX_FMT_YUV420P:
>>     case AV_PIX_FMT_YUVJ420P:
>> @@ -664,6 +727,8 @@ static enum AVPixelFormat get_format(HEVCContext *s, const HEVCSPS *sps)
>>         break;
>>     }
>> 
>> +    if (alpha_fmt != AV_PIX_FMT_NONE)
>> +        *fmt++ = alpha_fmt;
>>     *fmt++ = sps->pix_fmt;
>>     *fmt = AV_PIX_FMT_NONE;
>> 
>> @@ -3194,6 +3259,12 @@ static int hevc_frame_start(HEVCContext *s, HEVCLayerContext *l,
>>                 !sps->vui.common.video_signal_type_present_flag)
>>                 pix_fmt = sps_base->pix_fmt;
>> 
>> +            // Ignore range mismatch between base layer and alpha layer
>> +            if (ff_hevc_is_alpha_video(s) &&
>> +                sps_base->pix_fmt == AV_PIX_FMT_YUV420P &&
>> +                pix_fmt == AV_PIX_FMT_YUVJ420P)
>> +                pix_fmt = sps_base->pix_fmt;
>> +
>>             if (pix_fmt     != sps_base->pix_fmt ||
>>                 sps->width  != sps_base->width   ||
>>                 sps->height != sps_base->height) {
>> diff --git a/libavcodec/hevc/hevcdec.h b/libavcodec/hevc/hevcdec.h
>> index 4e95035688..b2b725b5cd 100644
>> --- a/libavcodec/hevc/hevcdec.h
>> +++ b/libavcodec/hevc/hevcdec.h
>> @@ -714,6 +714,8 @@ void ff_hevc_hls_residual_coding(HEVCLocalContext *lc, const HEVCPPS *pps,
>> 
>> void ff_hevc_hls_mvd_coding(HEVCLocalContext *lc, int x0, int y0, int log2_cb_size);
>> 
>> +int ff_hevc_is_alpha_video(const HEVCContext *s);
>> +
>> extern const uint8_t ff_hevc_qpel_extra_before[4];
>> extern const uint8_t ff_hevc_qpel_extra_after[4];
>> extern const uint8_t ff_hevc_qpel_extra[4];
>> diff --git a/libavcodec/hevc/refs.c b/libavcodec/hevc/refs.c
>> index dd7f7f95a8..da0bac8d9c 100644
>> --- a/libavcodec/hevc/refs.c
>> +++ b/libavcodec/hevc/refs.c
>> @@ -79,6 +79,30 @@ void ff_hevc_flush_dpb(HEVCContext *s)
>>     }
>> }
>> 
>> +static int replace_alpha_plane(AVFrame *alpha, AVFrame *base)
>> +{
>> +    AVBufferRef *base_a = av_frame_get_plane_buffer(base, 3);
>> +    uint8_t *data = alpha->data[0];
>> +    int ret;
>> +
>> +    for (int i = 0; i < FF_ARRAY_ELEMS(alpha->buf) && alpha->buf[i]; i++) {
>> +        AVBufferRef *buf = alpha->buf[i];
>> +
>> +        if (data >= buf->data && data < buf->data + buf->size) {
> 
> Pointer comparisons (other than equality/inquality comparisons) are
> undefined behavior unless the two pointers point into the same array (or
> one past the last element of an array).

av_frame_get_plane_buffer does the same compare. Any idea to fix this UB?

> 
>> +            ret = av_buffer_replace(&alpha->buf[i], base_a);
>> +            if (ret < 0)
>> +                return ret;
>> +
>> +            alpha->linesize[0] = base->linesize[3];
>> +            alpha->data[0] = base->data[3];
>> +
>> +            return 0;
>> +        }
>> +    }
>> +
>> +    return AVERROR_BUG;
>> +}
>> +
>> static HEVCFrame *alloc_frame(HEVCContext *s, HEVCLayerContext *l)
>> {
>>     const HEVCVPS *vps = l->sps->vps;
>> @@ -103,7 +127,7 @@ static HEVCFrame *alloc_frame(HEVCContext *s, HEVCLayerContext *l)
>>         }
>> 
>>         // add view ID side data if it's nontrivial
>> -        if (vps->nb_layers > 1 || view_id) {
>> +        if (!ff_hevc_is_alpha_video(s) && (vps->nb_layers > 1 || view_id)) {
>>             HEVCSEITDRDI *tdrdi = &s->sei.tdrdi;
>>             AVFrameSideData *sd = av_frame_side_data_new(&frame->f->side_data,
>>                                                          &frame->f->nb_side_data,
>> @@ -161,7 +185,15 @@ static HEVCFrame *alloc_frame(HEVCContext *s, HEVCLayerContext *l)
>>         if (ret < 0)
>>             goto fail;
>> 
>> +
>>         frame->pps = av_refstruct_ref_c(s->pps);
>> +        if (l != &s->layers[0] && ff_hevc_is_alpha_video(s)) {
>> +            AVFrame *alpha = frame->f;
>> +            AVFrame *base = s->layers[0].cur_frame->f;
>> +            ret = replace_alpha_plane(alpha, base);
>> +            if (ret < 0)
>> +                goto fail;
>> +        }
>> 
>>         return frame;
>> fail:
> 
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel@ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> 
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".

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^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [FFmpeg-devel] [PATCH v6 3/3] avcodec/hevc: Add alpha layer support
  2025-02-11 11:49   ` Zhao Zhili
@ 2025-02-11 12:12     ` Andreas Rheinhardt
  2025-02-11 12:48       ` Zhao Zhili
  0 siblings, 1 reply; 6+ messages in thread
From: Andreas Rheinhardt @ 2025-02-11 12:12 UTC (permalink / raw)
  To: ffmpeg-devel

Zhao Zhili:
> 
> 
>> On Feb 11, 2025, at 19:23, Andreas Rheinhardt <andreas.rheinhardt@outlook.com> wrote:
>>
>> Zhao Zhili:
>>> From: Zhao Zhili <zhilizhao@tencent.com>
>>>
>>> Signed-off-by: Zhao Zhili <zhilizhao@tencent.com>
>>> ---
>>> libavcodec/hevc/hevcdec.c | 73 ++++++++++++++++++++++++++++++++++++++-
>>> libavcodec/hevc/hevcdec.h |  2 ++
>>> libavcodec/hevc/refs.c    | 34 +++++++++++++++++-
>>> 3 files changed, 107 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/libavcodec/hevc/hevcdec.c b/libavcodec/hevc/hevcdec.c
>>> index e9c045f7a1..f71edf213b 100644
>>> --- a/libavcodec/hevc/hevcdec.c
>>> +++ b/libavcodec/hevc/hevcdec.c
>>> @@ -466,6 +466,25 @@ static int export_multilayer(HEVCContext *s, const HEVCVPS *vps)
>>>     return 0;
>>> }
>>>
>>> +int ff_hevc_is_alpha_video(const HEVCContext *s)
>>> +{
>>> +    const HEVCVPS *vps = s->vps;
>>> +    int ret = 0;
>>> +
>>> +    if (vps->nb_layers != 2 || !vps->layer_id_in_nuh[1])
>>> +        return 0;
>>> +
>>> +    /* decode_vps_ext() guarantees that SCALABILITY_AUXILIARY with AuxId other
>>> +     * than alpha cannot reach here.
>>> +     */
>>> +    ret = (s->vps->scalability_mask_flag & HEVC_SCALABILITY_AUXILIARY);
>>> +
>>> +    av_log(s->avctx, AV_LOG_DEBUG, "Multi layer video, %s alpha video\n",
>>> +           ret ? "is" : "not");
>>> +
>>> +    return ret;
>>> +}
>>> +
>>> static int setup_multilayer(HEVCContext *s, const HEVCVPS *vps)
>>> {
>>>     unsigned layers_active_output = 0, highest_layer;
>>> @@ -473,6 +492,18 @@ static int setup_multilayer(HEVCContext *s, const HEVCVPS *vps)
>>>     s->layers_active_output = 1;
>>>     s->layers_active_decode = 1;
>>>
>>> +    if (ff_hevc_is_alpha_video(s)) {
>>> +        const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(s->avctx->pix_fmt);
>>> +
>>> +        if (!(desc->flags & AV_PIX_FMT_FLAG_ALPHA))
>>> +            return 0;
>>> +
>>> +        s->layers_active_decode = (1 << vps->nb_layers) - 1;
>>> +        s->layers_active_output = 1;
>>> +
>>> +        return 0;
>>> +    }
>>> +
>>>     // nothing requested - decode base layer only
>>>     if (!s->nb_view_ids)
>>>         return 0;
>>> @@ -530,6 +561,34 @@ static int setup_multilayer(HEVCContext *s, const HEVCVPS *vps)
>>>     return 0;
>>> }
>>>
>>> +static enum AVPixelFormat map_to_alpha_format(HEVCContext *s,
>>> +                                              enum AVPixelFormat pix_fmt)
>>> +{
>>> +    switch (pix_fmt) {
>>> +    case AV_PIX_FMT_YUV420P:
>>> +    case AV_PIX_FMT_YUVJ420P:
>>> +        return AV_PIX_FMT_YUVA420P;
>>> +    case AV_PIX_FMT_YUV420P10:
>>> +        return AV_PIX_FMT_YUVA420P10;
>>> +    case AV_PIX_FMT_YUV444P:
>>> +        return AV_PIX_FMT_YUVA444P;
>>> +    case AV_PIX_FMT_YUV422P:
>>> +        return AV_PIX_FMT_YUVA422P;
>>> +    case AV_PIX_FMT_YUV422P10LE:
>>> +        return AV_PIX_FMT_YUVA422P10LE;
>>> +    case AV_PIX_FMT_YUV444P10:
>>> +        return AV_PIX_FMT_YUVA444P10;
>>> +    case AV_PIX_FMT_YUV444P12:
>>> +        return AV_PIX_FMT_YUVA444P12;
>>> +    case AV_PIX_FMT_YUV422P12:
>>> +        return AV_PIX_FMT_YUVA422P12;
>>> +    default:
>>> +        av_log(s->avctx, AV_LOG_WARNING, "No alpha pixel format map for %s\n",
>>> +               av_get_pix_fmt_name(pix_fmt));
>>> +        return AV_PIX_FMT_NONE;
>>> +    }
>>> +}
>>> +
>>> static enum AVPixelFormat get_format(HEVCContext *s, const HEVCSPS *sps)
>>> {
>>> #define HWACCEL_MAX (CONFIG_HEVC_DXVA2_HWACCEL + \
>>> @@ -540,9 +599,13 @@ static enum AVPixelFormat get_format(HEVCContext *s, const HEVCSPS *sps)
>>>                      CONFIG_HEVC_VIDEOTOOLBOX_HWACCEL + \
>>>                      CONFIG_HEVC_VDPAU_HWACCEL + \
>>>                      CONFIG_HEVC_VULKAN_HWACCEL)
>>> -    enum AVPixelFormat pix_fmts[HWACCEL_MAX + 2], *fmt = pix_fmts;
>>> +    enum AVPixelFormat pix_fmts[HWACCEL_MAX + 3], *fmt = pix_fmts;
>>> +    enum AVPixelFormat alpha_fmt = AV_PIX_FMT_NONE;
>>>     int ret;
>>>
>>> +    if (ff_hevc_is_alpha_video(s))
>>> +        alpha_fmt = map_to_alpha_format(s, sps->pix_fmt);
>>> +
>>>     switch (sps->pix_fmt) {
>>>     case AV_PIX_FMT_YUV420P:
>>>     case AV_PIX_FMT_YUVJ420P:
>>> @@ -664,6 +727,8 @@ static enum AVPixelFormat get_format(HEVCContext *s, const HEVCSPS *sps)
>>>         break;
>>>     }
>>>
>>> +    if (alpha_fmt != AV_PIX_FMT_NONE)
>>> +        *fmt++ = alpha_fmt;
>>>     *fmt++ = sps->pix_fmt;
>>>     *fmt = AV_PIX_FMT_NONE;
>>>
>>> @@ -3194,6 +3259,12 @@ static int hevc_frame_start(HEVCContext *s, HEVCLayerContext *l,
>>>                 !sps->vui.common.video_signal_type_present_flag)
>>>                 pix_fmt = sps_base->pix_fmt;
>>>
>>> +            // Ignore range mismatch between base layer and alpha layer
>>> +            if (ff_hevc_is_alpha_video(s) &&
>>> +                sps_base->pix_fmt == AV_PIX_FMT_YUV420P &&
>>> +                pix_fmt == AV_PIX_FMT_YUVJ420P)
>>> +                pix_fmt = sps_base->pix_fmt;
>>> +
>>>             if (pix_fmt     != sps_base->pix_fmt ||
>>>                 sps->width  != sps_base->width   ||
>>>                 sps->height != sps_base->height) {
>>> diff --git a/libavcodec/hevc/hevcdec.h b/libavcodec/hevc/hevcdec.h
>>> index 4e95035688..b2b725b5cd 100644
>>> --- a/libavcodec/hevc/hevcdec.h
>>> +++ b/libavcodec/hevc/hevcdec.h
>>> @@ -714,6 +714,8 @@ void ff_hevc_hls_residual_coding(HEVCLocalContext *lc, const HEVCPPS *pps,
>>>
>>> void ff_hevc_hls_mvd_coding(HEVCLocalContext *lc, int x0, int y0, int log2_cb_size);
>>>
>>> +int ff_hevc_is_alpha_video(const HEVCContext *s);
>>> +
>>> extern const uint8_t ff_hevc_qpel_extra_before[4];
>>> extern const uint8_t ff_hevc_qpel_extra_after[4];
>>> extern const uint8_t ff_hevc_qpel_extra[4];
>>> diff --git a/libavcodec/hevc/refs.c b/libavcodec/hevc/refs.c
>>> index dd7f7f95a8..da0bac8d9c 100644
>>> --- a/libavcodec/hevc/refs.c
>>> +++ b/libavcodec/hevc/refs.c
>>> @@ -79,6 +79,30 @@ void ff_hevc_flush_dpb(HEVCContext *s)
>>>     }
>>> }
>>>
>>> +static int replace_alpha_plane(AVFrame *alpha, AVFrame *base)
>>> +{
>>> +    AVBufferRef *base_a = av_frame_get_plane_buffer(base, 3);
>>> +    uint8_t *data = alpha->data[0];
>>> +    int ret;
>>> +
>>> +    for (int i = 0; i < FF_ARRAY_ELEMS(alpha->buf) && alpha->buf[i]; i++) {
>>> +        AVBufferRef *buf = alpha->buf[i];
>>> +
>>> +        if (data >= buf->data && data < buf->data + buf->size) {
>>
>> Pointer comparisons (other than equality/inquality comparisons) are
>> undefined behavior unless the two pointers point into the same array (or
>> one past the last element of an array).
> 
> av_frame_get_plane_buffer does the same compare. Any idea to fix this UB?

ISO C does not have a portable way to achieve this (except iterating
over buf->data[0..buf->size] and checking via ==).
In practice (in a flat memory space) casting to uintptr_t should work.

> 
>>
>>> +            ret = av_buffer_replace(&alpha->buf[i], base_a);
>>> +            if (ret < 0)
>>> +                return ret;
>>> +
>>> +            alpha->linesize[0] = base->linesize[3];
>>> +            alpha->data[0] = base->data[3];
>>> +
>>> +            return 0;
>>> +        }
>>> +    }
>>> +
>>> +    return AVERROR_BUG;
>>> +}
>>> +
>>> static HEVCFrame *alloc_frame(HEVCContext *s, HEVCLayerContext *l)
>>> {
>>>     const HEVCVPS *vps = l->sps->vps;
>>> @@ -103,7 +127,7 @@ static HEVCFrame *alloc_frame(HEVCContext *s, HEVCLayerContext *l)
>>>         }
>>>
>>>         // add view ID side data if it's nontrivial
>>> -        if (vps->nb_layers > 1 || view_id) {
>>> +        if (!ff_hevc_is_alpha_video(s) && (vps->nb_layers > 1 || view_id)) {
>>>             HEVCSEITDRDI *tdrdi = &s->sei.tdrdi;
>>>             AVFrameSideData *sd = av_frame_side_data_new(&frame->f->side_data,
>>>                                                          &frame->f->nb_side_data,
>>> @@ -161,7 +185,15 @@ static HEVCFrame *alloc_frame(HEVCContext *s, HEVCLayerContext *l)
>>>         if (ret < 0)
>>>             goto fail;
>>>
>>> +
>>>         frame->pps = av_refstruct_ref_c(s->pps);
>>> +        if (l != &s->layers[0] && ff_hevc_is_alpha_video(s)) {
>>> +            AVFrame *alpha = frame->f;
>>> +            AVFrame *base = s->layers[0].cur_frame->f;
>>> +            ret = replace_alpha_plane(alpha, base);
>>> +            if (ret < 0)
>>> +                goto fail;
>>> +        }
>>>
>>>         return frame;
>>> fail:
>>
>> _______________________________________________
>> ffmpeg-devel mailing list
>> ffmpeg-devel@ffmpeg.org
>> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>>
>> To unsubscribe, visit link above, or email
>> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
> 
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel@ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> 
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".

_______________________________________________
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To unsubscribe, visit link above, or email
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^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [FFmpeg-devel] [PATCH v6 3/3] avcodec/hevc: Add alpha layer support
  2025-02-11 12:12     ` Andreas Rheinhardt
@ 2025-02-11 12:48       ` Zhao Zhili
  2025-02-11 13:02         ` Andreas Rheinhardt
  0 siblings, 1 reply; 6+ messages in thread
From: Zhao Zhili @ 2025-02-11 12:48 UTC (permalink / raw)
  To: FFmpeg development discussions and patches



> On Feb 11, 2025, at 20:12, Andreas Rheinhardt <andreas.rheinhardt@outlook.com> wrote:
> 
> Zhao Zhili:
>> 
>> 
>>> On Feb 11, 2025, at 19:23, Andreas Rheinhardt <andreas.rheinhardt@outlook.com> wrote:
>>> 
>>> Zhao Zhili:
>>>> From: Zhao Zhili <zhilizhao@tencent.com>
>>>> 
>>>> Signed-off-by: Zhao Zhili <zhilizhao@tencent.com>
>>>> ---
>>>> libavcodec/hevc/hevcdec.c | 73 ++++++++++++++++++++++++++++++++++++++-
>>>> libavcodec/hevc/hevcdec.h |  2 ++
>>>> libavcodec/hevc/refs.c    | 34 +++++++++++++++++-
>>>> 3 files changed, 107 insertions(+), 2 deletions(-)
>>>> 
>>>> diff --git a/libavcodec/hevc/hevcdec.c b/libavcodec/hevc/hevcdec.c
>>>> index e9c045f7a1..f71edf213b 100644
>>>> --- a/libavcodec/hevc/hevcdec.c
>>>> +++ b/libavcodec/hevc/hevcdec.c
>>>> @@ -466,6 +466,25 @@ static int export_multilayer(HEVCContext *s, const HEVCVPS *vps)
>>>>    return 0;
>>>> }
>>>> 
>>>> +int ff_hevc_is_alpha_video(const HEVCContext *s)
>>>> +{
>>>> +    const HEVCVPS *vps = s->vps;
>>>> +    int ret = 0;
>>>> +
>>>> +    if (vps->nb_layers != 2 || !vps->layer_id_in_nuh[1])
>>>> +        return 0;
>>>> +
>>>> +    /* decode_vps_ext() guarantees that SCALABILITY_AUXILIARY with AuxId other
>>>> +     * than alpha cannot reach here.
>>>> +     */
>>>> +    ret = (s->vps->scalability_mask_flag & HEVC_SCALABILITY_AUXILIARY);
>>>> +
>>>> +    av_log(s->avctx, AV_LOG_DEBUG, "Multi layer video, %s alpha video\n",
>>>> +           ret ? "is" : "not");
>>>> +
>>>> +    return ret;
>>>> +}
>>>> +
>>>> static int setup_multilayer(HEVCContext *s, const HEVCVPS *vps)
>>>> {
>>>>    unsigned layers_active_output = 0, highest_layer;
>>>> @@ -473,6 +492,18 @@ static int setup_multilayer(HEVCContext *s, const HEVCVPS *vps)
>>>>    s->layers_active_output = 1;
>>>>    s->layers_active_decode = 1;
>>>> 
>>>> +    if (ff_hevc_is_alpha_video(s)) {
>>>> +        const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(s->avctx->pix_fmt);
>>>> +
>>>> +        if (!(desc->flags & AV_PIX_FMT_FLAG_ALPHA))
>>>> +            return 0;
>>>> +
>>>> +        s->layers_active_decode = (1 << vps->nb_layers) - 1;
>>>> +        s->layers_active_output = 1;
>>>> +
>>>> +        return 0;
>>>> +    }
>>>> +
>>>>    // nothing requested - decode base layer only
>>>>    if (!s->nb_view_ids)
>>>>        return 0;
>>>> @@ -530,6 +561,34 @@ static int setup_multilayer(HEVCContext *s, const HEVCVPS *vps)
>>>>    return 0;
>>>> }
>>>> 
>>>> +static enum AVPixelFormat map_to_alpha_format(HEVCContext *s,
>>>> +                                              enum AVPixelFormat pix_fmt)
>>>> +{
>>>> +    switch (pix_fmt) {
>>>> +    case AV_PIX_FMT_YUV420P:
>>>> +    case AV_PIX_FMT_YUVJ420P:
>>>> +        return AV_PIX_FMT_YUVA420P;
>>>> +    case AV_PIX_FMT_YUV420P10:
>>>> +        return AV_PIX_FMT_YUVA420P10;
>>>> +    case AV_PIX_FMT_YUV444P:
>>>> +        return AV_PIX_FMT_YUVA444P;
>>>> +    case AV_PIX_FMT_YUV422P:
>>>> +        return AV_PIX_FMT_YUVA422P;
>>>> +    case AV_PIX_FMT_YUV422P10LE:
>>>> +        return AV_PIX_FMT_YUVA422P10LE;
>>>> +    case AV_PIX_FMT_YUV444P10:
>>>> +        return AV_PIX_FMT_YUVA444P10;
>>>> +    case AV_PIX_FMT_YUV444P12:
>>>> +        return AV_PIX_FMT_YUVA444P12;
>>>> +    case AV_PIX_FMT_YUV422P12:
>>>> +        return AV_PIX_FMT_YUVA422P12;
>>>> +    default:
>>>> +        av_log(s->avctx, AV_LOG_WARNING, "No alpha pixel format map for %s\n",
>>>> +               av_get_pix_fmt_name(pix_fmt));
>>>> +        return AV_PIX_FMT_NONE;
>>>> +    }
>>>> +}
>>>> +
>>>> static enum AVPixelFormat get_format(HEVCContext *s, const HEVCSPS *sps)
>>>> {
>>>> #define HWACCEL_MAX (CONFIG_HEVC_DXVA2_HWACCEL + \
>>>> @@ -540,9 +599,13 @@ static enum AVPixelFormat get_format(HEVCContext *s, const HEVCSPS *sps)
>>>>                     CONFIG_HEVC_VIDEOTOOLBOX_HWACCEL + \
>>>>                     CONFIG_HEVC_VDPAU_HWACCEL + \
>>>>                     CONFIG_HEVC_VULKAN_HWACCEL)
>>>> -    enum AVPixelFormat pix_fmts[HWACCEL_MAX + 2], *fmt = pix_fmts;
>>>> +    enum AVPixelFormat pix_fmts[HWACCEL_MAX + 3], *fmt = pix_fmts;
>>>> +    enum AVPixelFormat alpha_fmt = AV_PIX_FMT_NONE;
>>>>    int ret;
>>>> 
>>>> +    if (ff_hevc_is_alpha_video(s))
>>>> +        alpha_fmt = map_to_alpha_format(s, sps->pix_fmt);
>>>> +
>>>>    switch (sps->pix_fmt) {
>>>>    case AV_PIX_FMT_YUV420P:
>>>>    case AV_PIX_FMT_YUVJ420P:
>>>> @@ -664,6 +727,8 @@ static enum AVPixelFormat get_format(HEVCContext *s, const HEVCSPS *sps)
>>>>        break;
>>>>    }
>>>> 
>>>> +    if (alpha_fmt != AV_PIX_FMT_NONE)
>>>> +        *fmt++ = alpha_fmt;
>>>>    *fmt++ = sps->pix_fmt;
>>>>    *fmt = AV_PIX_FMT_NONE;
>>>> 
>>>> @@ -3194,6 +3259,12 @@ static int hevc_frame_start(HEVCContext *s, HEVCLayerContext *l,
>>>>                !sps->vui.common.video_signal_type_present_flag)
>>>>                pix_fmt = sps_base->pix_fmt;
>>>> 
>>>> +            // Ignore range mismatch between base layer and alpha layer
>>>> +            if (ff_hevc_is_alpha_video(s) &&
>>>> +                sps_base->pix_fmt == AV_PIX_FMT_YUV420P &&
>>>> +                pix_fmt == AV_PIX_FMT_YUVJ420P)
>>>> +                pix_fmt = sps_base->pix_fmt;
>>>> +
>>>>            if (pix_fmt     != sps_base->pix_fmt ||
>>>>                sps->width  != sps_base->width   ||
>>>>                sps->height != sps_base->height) {
>>>> diff --git a/libavcodec/hevc/hevcdec.h b/libavcodec/hevc/hevcdec.h
>>>> index 4e95035688..b2b725b5cd 100644
>>>> --- a/libavcodec/hevc/hevcdec.h
>>>> +++ b/libavcodec/hevc/hevcdec.h
>>>> @@ -714,6 +714,8 @@ void ff_hevc_hls_residual_coding(HEVCLocalContext *lc, const HEVCPPS *pps,
>>>> 
>>>> void ff_hevc_hls_mvd_coding(HEVCLocalContext *lc, int x0, int y0, int log2_cb_size);
>>>> 
>>>> +int ff_hevc_is_alpha_video(const HEVCContext *s);
>>>> +
>>>> extern const uint8_t ff_hevc_qpel_extra_before[4];
>>>> extern const uint8_t ff_hevc_qpel_extra_after[4];
>>>> extern const uint8_t ff_hevc_qpel_extra[4];
>>>> diff --git a/libavcodec/hevc/refs.c b/libavcodec/hevc/refs.c
>>>> index dd7f7f95a8..da0bac8d9c 100644
>>>> --- a/libavcodec/hevc/refs.c
>>>> +++ b/libavcodec/hevc/refs.c
>>>> @@ -79,6 +79,30 @@ void ff_hevc_flush_dpb(HEVCContext *s)
>>>>    }
>>>> }
>>>> 
>>>> +static int replace_alpha_plane(AVFrame *alpha, AVFrame *base)
>>>> +{
>>>> +    AVBufferRef *base_a = av_frame_get_plane_buffer(base, 3);
>>>> +    uint8_t *data = alpha->data[0];
>>>> +    int ret;
>>>> +
>>>> +    for (int i = 0; i < FF_ARRAY_ELEMS(alpha->buf) && alpha->buf[i]; i++) {
>>>> +        AVBufferRef *buf = alpha->buf[i];
>>>> +
>>>> +        if (data >= buf->data && data < buf->data + buf->size) {
>>> 
>>> Pointer comparisons (other than equality/inquality comparisons) are
>>> undefined behavior unless the two pointers point into the same array (or
>>> one past the last element of an array).
>> 
>> av_frame_get_plane_buffer does the same compare. Any idea to fix this UB?
> 
> ISO C does not have a portable way to achieve this (except iterating
> over buf->data[0..buf->size] and checking via ==).
> In practice (in a flat memory space) casting to uintptr_t should work.

What’s the difference with and without cast in practice?

> 
>> 
>>> 
>>>> +            ret = av_buffer_replace(&alpha->buf[i], base_a);
>>>> +            if (ret < 0)
>>>> +                return ret;
>>>> +
>>>> +            alpha->linesize[0] = base->linesize[3];
>>>> +            alpha->data[0] = base->data[3];
>>>> +
>>>> +            return 0;
>>>> +        }
>>>> +    }
>>>> +
>>>> +    return AVERROR_BUG;
>>>> +}
>>>> +
>>>> static HEVCFrame *alloc_frame(HEVCContext *s, HEVCLayerContext *l)
>>>> {
>>>>    const HEVCVPS *vps = l->sps->vps;
>>>> @@ -103,7 +127,7 @@ static HEVCFrame *alloc_frame(HEVCContext *s, HEVCLayerContext *l)
>>>>        }
>>>> 
>>>>        // add view ID side data if it's nontrivial
>>>> -        if (vps->nb_layers > 1 || view_id) {
>>>> +        if (!ff_hevc_is_alpha_video(s) && (vps->nb_layers > 1 || view_id)) {
>>>>            HEVCSEITDRDI *tdrdi = &s->sei.tdrdi;
>>>>            AVFrameSideData *sd = av_frame_side_data_new(&frame->f->side_data,
>>>>                                                         &frame->f->nb_side_data,
>>>> @@ -161,7 +185,15 @@ static HEVCFrame *alloc_frame(HEVCContext *s, HEVCLayerContext *l)
>>>>        if (ret < 0)
>>>>            goto fail;
>>>> 
>>>> +
>>>>        frame->pps = av_refstruct_ref_c(s->pps);
>>>> +        if (l != &s->layers[0] && ff_hevc_is_alpha_video(s)) {
>>>> +            AVFrame *alpha = frame->f;
>>>> +            AVFrame *base = s->layers[0].cur_frame->f;
>>>> +            ret = replace_alpha_plane(alpha, base);
>>>> +            if (ret < 0)
>>>> +                goto fail;
>>>> +        }
>>>> 
>>>>        return frame;
>>>> fail:
>>> 
>>> _______________________________________________
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>>> ffmpeg-devel@ffmpeg.org
>>> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>>> 
>>> To unsubscribe, visit link above, or email
>>> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
>> 
>> _______________________________________________
>> ffmpeg-devel mailing list
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>> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>> 
>> To unsubscribe, visit link above, or email
>> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
> 
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> ffmpeg-devel mailing list
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> 
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".

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^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [FFmpeg-devel] [PATCH v6 3/3] avcodec/hevc: Add alpha layer support
  2025-02-11 12:48       ` Zhao Zhili
@ 2025-02-11 13:02         ` Andreas Rheinhardt
  0 siblings, 0 replies; 6+ messages in thread
From: Andreas Rheinhardt @ 2025-02-11 13:02 UTC (permalink / raw)
  To: ffmpeg-devel

Zhao Zhili:
> 
> 
>> On Feb 11, 2025, at 20:12, Andreas Rheinhardt <andreas.rheinhardt@outlook.com> wrote:
>>
>> Zhao Zhili:
>>>
>>>
>>>> On Feb 11, 2025, at 19:23, Andreas Rheinhardt <andreas.rheinhardt@outlook.com> wrote:
>>>>
>>>> Zhao Zhili:
>>>>> From: Zhao Zhili <zhilizhao@tencent.com>
>>>>>
>>>>> Signed-off-by: Zhao Zhili <zhilizhao@tencent.com>
>>>>> ---
>>>>> libavcodec/hevc/hevcdec.c | 73 ++++++++++++++++++++++++++++++++++++++-
>>>>> libavcodec/hevc/hevcdec.h |  2 ++
>>>>> libavcodec/hevc/refs.c    | 34 +++++++++++++++++-
>>>>> 3 files changed, 107 insertions(+), 2 deletions(-)
>>>>>
>>>>> diff --git a/libavcodec/hevc/hevcdec.c b/libavcodec/hevc/hevcdec.c
>>>>> index e9c045f7a1..f71edf213b 100644
>>>>> --- a/libavcodec/hevc/hevcdec.c
>>>>> +++ b/libavcodec/hevc/hevcdec.c
>>>>> @@ -466,6 +466,25 @@ static int export_multilayer(HEVCContext *s, const HEVCVPS *vps)
>>>>>    return 0;
>>>>> }
>>>>>
>>>>> +int ff_hevc_is_alpha_video(const HEVCContext *s)
>>>>> +{
>>>>> +    const HEVCVPS *vps = s->vps;
>>>>> +    int ret = 0;
>>>>> +
>>>>> +    if (vps->nb_layers != 2 || !vps->layer_id_in_nuh[1])
>>>>> +        return 0;
>>>>> +
>>>>> +    /* decode_vps_ext() guarantees that SCALABILITY_AUXILIARY with AuxId other
>>>>> +     * than alpha cannot reach here.
>>>>> +     */
>>>>> +    ret = (s->vps->scalability_mask_flag & HEVC_SCALABILITY_AUXILIARY);
>>>>> +
>>>>> +    av_log(s->avctx, AV_LOG_DEBUG, "Multi layer video, %s alpha video\n",
>>>>> +           ret ? "is" : "not");
>>>>> +
>>>>> +    return ret;
>>>>> +}
>>>>> +
>>>>> static int setup_multilayer(HEVCContext *s, const HEVCVPS *vps)
>>>>> {
>>>>>    unsigned layers_active_output = 0, highest_layer;
>>>>> @@ -473,6 +492,18 @@ static int setup_multilayer(HEVCContext *s, const HEVCVPS *vps)
>>>>>    s->layers_active_output = 1;
>>>>>    s->layers_active_decode = 1;
>>>>>
>>>>> +    if (ff_hevc_is_alpha_video(s)) {
>>>>> +        const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(s->avctx->pix_fmt);
>>>>> +
>>>>> +        if (!(desc->flags & AV_PIX_FMT_FLAG_ALPHA))
>>>>> +            return 0;
>>>>> +
>>>>> +        s->layers_active_decode = (1 << vps->nb_layers) - 1;
>>>>> +        s->layers_active_output = 1;
>>>>> +
>>>>> +        return 0;
>>>>> +    }
>>>>> +
>>>>>    // nothing requested - decode base layer only
>>>>>    if (!s->nb_view_ids)
>>>>>        return 0;
>>>>> @@ -530,6 +561,34 @@ static int setup_multilayer(HEVCContext *s, const HEVCVPS *vps)
>>>>>    return 0;
>>>>> }
>>>>>
>>>>> +static enum AVPixelFormat map_to_alpha_format(HEVCContext *s,
>>>>> +                                              enum AVPixelFormat pix_fmt)
>>>>> +{
>>>>> +    switch (pix_fmt) {
>>>>> +    case AV_PIX_FMT_YUV420P:
>>>>> +    case AV_PIX_FMT_YUVJ420P:
>>>>> +        return AV_PIX_FMT_YUVA420P;
>>>>> +    case AV_PIX_FMT_YUV420P10:
>>>>> +        return AV_PIX_FMT_YUVA420P10;
>>>>> +    case AV_PIX_FMT_YUV444P:
>>>>> +        return AV_PIX_FMT_YUVA444P;
>>>>> +    case AV_PIX_FMT_YUV422P:
>>>>> +        return AV_PIX_FMT_YUVA422P;
>>>>> +    case AV_PIX_FMT_YUV422P10LE:
>>>>> +        return AV_PIX_FMT_YUVA422P10LE;
>>>>> +    case AV_PIX_FMT_YUV444P10:
>>>>> +        return AV_PIX_FMT_YUVA444P10;
>>>>> +    case AV_PIX_FMT_YUV444P12:
>>>>> +        return AV_PIX_FMT_YUVA444P12;
>>>>> +    case AV_PIX_FMT_YUV422P12:
>>>>> +        return AV_PIX_FMT_YUVA422P12;
>>>>> +    default:
>>>>> +        av_log(s->avctx, AV_LOG_WARNING, "No alpha pixel format map for %s\n",
>>>>> +               av_get_pix_fmt_name(pix_fmt));
>>>>> +        return AV_PIX_FMT_NONE;
>>>>> +    }
>>>>> +}
>>>>> +
>>>>> static enum AVPixelFormat get_format(HEVCContext *s, const HEVCSPS *sps)
>>>>> {
>>>>> #define HWACCEL_MAX (CONFIG_HEVC_DXVA2_HWACCEL + \
>>>>> @@ -540,9 +599,13 @@ static enum AVPixelFormat get_format(HEVCContext *s, const HEVCSPS *sps)
>>>>>                     CONFIG_HEVC_VIDEOTOOLBOX_HWACCEL + \
>>>>>                     CONFIG_HEVC_VDPAU_HWACCEL + \
>>>>>                     CONFIG_HEVC_VULKAN_HWACCEL)
>>>>> -    enum AVPixelFormat pix_fmts[HWACCEL_MAX + 2], *fmt = pix_fmts;
>>>>> +    enum AVPixelFormat pix_fmts[HWACCEL_MAX + 3], *fmt = pix_fmts;
>>>>> +    enum AVPixelFormat alpha_fmt = AV_PIX_FMT_NONE;
>>>>>    int ret;
>>>>>
>>>>> +    if (ff_hevc_is_alpha_video(s))
>>>>> +        alpha_fmt = map_to_alpha_format(s, sps->pix_fmt);
>>>>> +
>>>>>    switch (sps->pix_fmt) {
>>>>>    case AV_PIX_FMT_YUV420P:
>>>>>    case AV_PIX_FMT_YUVJ420P:
>>>>> @@ -664,6 +727,8 @@ static enum AVPixelFormat get_format(HEVCContext *s, const HEVCSPS *sps)
>>>>>        break;
>>>>>    }
>>>>>
>>>>> +    if (alpha_fmt != AV_PIX_FMT_NONE)
>>>>> +        *fmt++ = alpha_fmt;
>>>>>    *fmt++ = sps->pix_fmt;
>>>>>    *fmt = AV_PIX_FMT_NONE;
>>>>>
>>>>> @@ -3194,6 +3259,12 @@ static int hevc_frame_start(HEVCContext *s, HEVCLayerContext *l,
>>>>>                !sps->vui.common.video_signal_type_present_flag)
>>>>>                pix_fmt = sps_base->pix_fmt;
>>>>>
>>>>> +            // Ignore range mismatch between base layer and alpha layer
>>>>> +            if (ff_hevc_is_alpha_video(s) &&
>>>>> +                sps_base->pix_fmt == AV_PIX_FMT_YUV420P &&
>>>>> +                pix_fmt == AV_PIX_FMT_YUVJ420P)
>>>>> +                pix_fmt = sps_base->pix_fmt;
>>>>> +
>>>>>            if (pix_fmt     != sps_base->pix_fmt ||
>>>>>                sps->width  != sps_base->width   ||
>>>>>                sps->height != sps_base->height) {
>>>>> diff --git a/libavcodec/hevc/hevcdec.h b/libavcodec/hevc/hevcdec.h
>>>>> index 4e95035688..b2b725b5cd 100644
>>>>> --- a/libavcodec/hevc/hevcdec.h
>>>>> +++ b/libavcodec/hevc/hevcdec.h
>>>>> @@ -714,6 +714,8 @@ void ff_hevc_hls_residual_coding(HEVCLocalContext *lc, const HEVCPPS *pps,
>>>>>
>>>>> void ff_hevc_hls_mvd_coding(HEVCLocalContext *lc, int x0, int y0, int log2_cb_size);
>>>>>
>>>>> +int ff_hevc_is_alpha_video(const HEVCContext *s);
>>>>> +
>>>>> extern const uint8_t ff_hevc_qpel_extra_before[4];
>>>>> extern const uint8_t ff_hevc_qpel_extra_after[4];
>>>>> extern const uint8_t ff_hevc_qpel_extra[4];
>>>>> diff --git a/libavcodec/hevc/refs.c b/libavcodec/hevc/refs.c
>>>>> index dd7f7f95a8..da0bac8d9c 100644
>>>>> --- a/libavcodec/hevc/refs.c
>>>>> +++ b/libavcodec/hevc/refs.c
>>>>> @@ -79,6 +79,30 @@ void ff_hevc_flush_dpb(HEVCContext *s)
>>>>>    }
>>>>> }
>>>>>
>>>>> +static int replace_alpha_plane(AVFrame *alpha, AVFrame *base)
>>>>> +{
>>>>> +    AVBufferRef *base_a = av_frame_get_plane_buffer(base, 3);
>>>>> +    uint8_t *data = alpha->data[0];
>>>>> +    int ret;
>>>>> +
>>>>> +    for (int i = 0; i < FF_ARRAY_ELEMS(alpha->buf) && alpha->buf[i]; i++) {
>>>>> +        AVBufferRef *buf = alpha->buf[i];
>>>>> +
>>>>> +        if (data >= buf->data && data < buf->data + buf->size) {
>>>>
>>>> Pointer comparisons (other than equality/inquality comparisons) are
>>>> undefined behavior unless the two pointers point into the same array (or
>>>> one past the last element of an array).
>>>
>>> av_frame_get_plane_buffer does the same compare. Any idea to fix this UB?
>>
>> ISO C does not have a portable way to achieve this (except iterating
>> over buf->data[0..buf->size] and checking via ==).
>> In practice (in a flat memory space) casting to uintptr_t should work.
> 
> What’s the difference with and without cast in practice?

I don't know any atm; maybe future versions of USan will warn about
invalid pointer comparisons?

> 
>>
>>>
>>>>
>>>>> +            ret = av_buffer_replace(&alpha->buf[i], base_a);
>>>>> +            if (ret < 0)
>>>>> +                return ret;
>>>>> +
>>>>> +            alpha->linesize[0] = base->linesize[3];
>>>>> +            alpha->data[0] = base->data[3];
>>>>> +
>>>>> +            return 0;
>>>>> +        }
>>>>> +    }
>>>>> +
>>>>> +    return AVERROR_BUG;
>>>>> +}
>>>>> +
>>>>> static HEVCFrame *alloc_frame(HEVCContext *s, HEVCLayerContext *l)
>>>>> {
>>>>>    const HEVCVPS *vps = l->sps->vps;
>>>>> @@ -103,7 +127,7 @@ static HEVCFrame *alloc_frame(HEVCContext *s, HEVCLayerContext *l)
>>>>>        }
>>>>>
>>>>>        // add view ID side data if it's nontrivial
>>>>> -        if (vps->nb_layers > 1 || view_id) {
>>>>> +        if (!ff_hevc_is_alpha_video(s) && (vps->nb_layers > 1 || view_id)) {
>>>>>            HEVCSEITDRDI *tdrdi = &s->sei.tdrdi;
>>>>>            AVFrameSideData *sd = av_frame_side_data_new(&frame->f->side_data,
>>>>>                                                         &frame->f->nb_side_data,
>>>>> @@ -161,7 +185,15 @@ static HEVCFrame *alloc_frame(HEVCContext *s, HEVCLayerContext *l)
>>>>>        if (ret < 0)
>>>>>            goto fail;
>>>>>
>>>>> +
>>>>>        frame->pps = av_refstruct_ref_c(s->pps);
>>>>> +        if (l != &s->layers[0] && ff_hevc_is_alpha_video(s)) {
>>>>> +            AVFrame *alpha = frame->f;
>>>>> +            AVFrame *base = s->layers[0].cur_frame->f;
>>>>> +            ret = replace_alpha_plane(alpha, base);
>>>>> +            if (ret < 0)
>>>>> +                goto fail;
>>>>> +        }
>>>>>
>>>>>        return frame;
>>>>> fail:
>>>>
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^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2025-02-11 13:02 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2025-02-11 10:40 [FFmpeg-devel] [PATCH v6 3/3] avcodec/hevc: Add alpha layer support Zhao Zhili
2025-02-11 11:23 ` Andreas Rheinhardt
2025-02-11 11:49   ` Zhao Zhili
2025-02-11 12:12     ` Andreas Rheinhardt
2025-02-11 12:48       ` Zhao Zhili
2025-02-11 13:02         ` Andreas Rheinhardt

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